Process for dyeing acidyl celluloses



Fatented Oct. 11, 1925" UNITED STATES PATENT QFFEQEQ.

PAUL BABE, OF LEVERKUSEN, NEAR GOLOGNE-QN-THE-RHINE, AND WILHEUMSCHEPSS, OF WIESDORF, NEAR COLOGNE-ON-THE-RHINE, GERMANY, ASSIGNGJPQS,BY MESNE ASSIGNMENTS, TO GRASSELLI DYESTUFF CORPORATION, E IQEVI?- YUEK,

H. Y. A CORPORATION OF DELAWARE.

PROCESS FOR DYEING ACIDYL CELLULOSES.

No Drawing. Original application filed March 3, 1924, Serial No.696,675, and in Germany may 29, 1923. Divided and this application filedDecember 10, 1924. Serial No. 755,037,

It is well known that acidyl celluloses have only a small absorbtivepower for dyestufi's. Attempts have, therefore, not been lacking toavoid this defect. A process is described, for instance, in GermanPatent No.

355,533, Which allows of the direct dyeing of cellulose acetate silk, bythe addition to the dye bath of one or more protective colloids, organicacids, and larger quantities of Waterssoluble salts, particularlychlorides. British Patent 179,384 also recommends the employment ofmetallic salts such as sodium stannate, magenta, etc, With thesimultaneous addition of colloids.

The noteworthy fact has now been estab lished, that salts of the oxyacids of chlorine, as for instance chlorates, etc., are suitable inquite a peculiar degree as additions in dyein acidyl cellulose, e. g.cellulose acetate 29 sil films, etc. or their transformation products.The use of protective colloids is superfluous. Even relativel smallquantities of these salts produce s ades of hitherto unattainable depth.

Eammple 1.1 part by weight of chrysoidine G extra is dissolved in 1000parts by weight of water and 5 parts by Weight of chlorate of otassiumKClO are added. Ratio 1:20. yeing temperature 70. Time so minutes.Instead of chlorate of potassium the chlorates of ammonium, sodium,

magnesium, calcium or zinc and further of such organic bases asmonomethlylamine, di-methylamine, etc, guanidine, pyridine andpiperidine, may be used.

Other dyestutt's or their salts, as for instance methylene blue,rhodulin red, B, saf ranine, auramine, Bismarck brown, rhodiulin yellow,rhodulin blue 6G (nitrate), turquoise blue G, rhodamin 6G extra, newmethylene blue F, and many others can be fixed on cellulose acetatesilks in this manner, with extraordinary depth of shade.

This application is a division of our appli cation SerialNumber 696,675filed March 3, 1924:. 1

We claim 1. Process of dyein acidyl celluloses characterized in and byhe fact that the acidyl celluloses are dyed in a neutral bath cona saltof an oxy acid of chlorine.

tainirfgg 2. rocess of dyein acidyl celluloses char-' acterized in andby t e fact that the acidyl celluloses are dyed in a neutral bathcontaining potassium chlorate. 3. A neutral dyeing compositioncomprislng a dye and a salt of an oxy acid of chlorine.

In testimony whereof, We afiix our signatures.

PAUL RABE. WILHELM SOHEPSS.

